1. Field of the Invention
The present invention relates to communication networks, and more specifically to a method and apparatus for providing a flexible Ethernet bridge.
2. Related Art
Ethernet bridge generally refers to a system which transfers Ethernet packets from one network to the other based on operation at the layer-2 level of the Open Systems Interconnect (OSI) model. In general, an Ethernet bridge examines a destination address of an Ethernet packet to determine a specific one of potentially several ports, on which to forward the packet.
To facilitate such forwarding on a single port where possible, Ethernet bridges generally maintain an address table indicating the specific port/direction on which a machine with a specific Ethernet address is reachable/available. The address table is typically populated based on the source address (and the port on which the packet is received) of each Ethernet packet received, as is well known in the relevant arts. While forwarding an Ethernet packet, if the destination address is not present in the table, the packet may be forwarded on all ports, and is often referred to as flooding.
Ethernet bridges often need to be implemented supporting several requirements. For example, it may be required to reduce the cost of an Ethernet bridge at least in situation in which the Ethernet bridge is integrated with devices such as IP phones and DSL routers. In addition, an Ethernet bridge may need to support features such as Virtual LANs (VLANS), which generally minimizes unneeded flooding and/or broadcast packets across all LANs.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.